The string appears to be a combination of:
: When you download a game from the PlayStation Store, the system uses PKG files to install the content to your internal hard drive. Homebrew & "Top" PKGs : Users with modified consoles (such as those running Custom Firmware i the sims 3 ps3 pkg top
Likely intent: User is looking for a high-quality or fully featured PKG file of The Sims 3 for PS3 to install on a modded console (e.g., HEN, CFW). i the sims 3 ps3 pkg top
The Ultimate Guide to The Sims 3 on PS3: PKG Downloads, Top Features, and Gameplay i the sims 3 ps3 pkg top